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adequate ventilation to prevent exposure of the flow pump or the squeeze bulb. The test opera-
person conducting the fit test or the buildup of ir- tor shall begin at least 12 inches from the
ritant smoke in the general atmosphere.
(b) Sensitivity Screening Check
The person to be tested must demonstrate his
or her ability to detect a weak concentration of
the irritant smoke.
(1) The test operator shall break both ends of a
ventilation smoke tube containing stannic
chloride, and attach one end of the smoke tube
to a low flow air pump set to deliver 200 milli-
liters per minute, or an aspirator squeeze bulb.
The test operator shall cover the other end of
the smoke tube with a short piece of tubing to
prevent potential injury from the jagged end of
the smoke tube.
(2) The test operator shall advise the test sub-
ject that the smoke can be irritating to the eyes, failed. The person being retested must repeat
lungs, and nasal passages and instruct the
subject to keep his/her eyes closed while the
test is performed.
(3) The test subject shall be allowed to smell a
weak concentration of the irritant smoke be-
fore the respirator is donned to become famil-
iar with its irritating properties and to
determine if he/she can detect the irritating
properties of the smoke. The test operator shall
carefully direct a small amount of the irritant
smoke in the test subject’s direction to deter-
mine that he/she can detect it.
(c) Irritant Smoke Fit Test Procedure
(1) The person being fit tested shall don the
respirator without assistance, and perform the
required user seal check(s).
(2) The test subject shall be instructed to keep
his/her eyes closed.
(3) The test operator shall direct the stream of
irritant smoke from the smoke tube toward the
faceseal area of the test subject, using the low
105
facepiece and move the smoke stream around
the whole perimeter of the mask. The operator
shall gradually make two more passes around
the perimeter of the mask, moving to within
six inches of the respirator.
(4) If the person being tested has not had an in-
voluntary response and/or detected the irri-
tant smoke, proceed with the test exercises.
(5) The exercises identified in section I.A. 14. of
this appendix shall be performed by the test
subject while the respirator seal is being con-
tinually challenged by the smoke, directed
around the perimeter of the respirator at a dis-
tance of six inches.
(6) If the person being fit tested reports detect-
ing the irritant smoke at any time, the test is
the entire sensitivity check and fit test proce-
dure.
(7) Each test subject passing the irritant smoke
test without evidence of a response (involun-
tary cough, irritation) shall be given a second
sensitivity screening check, with the smoke
from the same smoke tube used during the fit
test, once the respirator has been removed, to
determine whether he/she still reacts to the
smoke. Failure to evoke a response shall void
the fit test.
(8) If a response is produced during this sec-
ond sensitivity check, then the fit test is passed.
C. Quantitative Fit Test (QNFT) Protocols
The following quantitative fit testing proce-
dures have been demonstrated to be accept-
able: Quantitative fit testing using a
non-hazardous test aerosol (such as corn oil,
polyethylene glycol 400 [PEG 400], di-2-ethyl
hexyl sebacate [DEHS], or sodium chloride)
generated in a test chamber, and employing
instrumentation to quantify the fit of the respi-